Resetting a Locked Version 2 Gearbox

If your AEG airsoft gun suddenly stops working, it could mean several things:

Battery is dead.

Motor is burnt.

Wires are bad.

Gearbox is locked.

This article provides a quick and simple method to reset your gearbox, without taking it all apart. There are cases where you do have to take the entire gearbox apart. But you should try this method first.

Before you attempt this procedure, troubleshoot your airsoft gun to ensure it's not one of the first three problems. You can weed them out by detaching the motor from the gearbox (following the steps in this article) and activate the gun to see if the motor turns. If it does, then it's likely a locked gearbox.

A defective battery or a battery with a low charge will activate the motor when the motor is not attached to the gearbox. So make sure you have a good battery to compare to. If the good battery fires the gun, then your gearbox may not be jammed, your battery is just dead.

Disassembly

The motor on a version 2 gearbox is located inside the handgrip. The base of the handgrip has a plate with two small screws (see photo below). The big flat screw in the middle is to adjust the motor tension to the gearbox. Unscrew the two small screws to remove the plate.

After removing the handgrip plate, you'll see the motor and attached wires (see photo below). Detach the wires and remove the motor. Once you have removed the motor from the handgrip, you can reattach the wires to test the battery, wires, and motor all at once. If the motor turns fine, then proceed with this reset procedure.

Motor Jam

It's possible that your motor pinion gear has jammed in the gearbox. By removing the motor, you could have reset the lockup already. Try putting the motor and the handgrip base plate back, fire the gun in semi-auto, and see if it works. If it does, then you are done. Otherwise continue to the next section.

Reset Anti-Reversal Latch

Next step is to remove the handgrip. There are two screws inside the motor slot (see photo below). Unscrew the two to four screws. Be careful that the screws don't fall into the gearbox. Once you've unscrewed the handgrip, you can remove it easily.

Before going any further, you'll have to make the anti-reversal latch resetting tool (see photo below). It's just a paper clip bent into a small hook. The hook should be no bigger than half the size of the motor insertion hole. If it is bigger than that, you won't be able to get the hook around the anti-reversal latch.

With the anti-reversal latch resetting tool, insert it and hook it onto the anti-reversal latch. The anti-reversal latch is the long metal extending from the bottom of the motor insertion hole (see photo below) when the gun is pointed away from you.

Then with a quick pull on the hook, you should have loosen the lock. Plug in the battery, push the motor into the gearbox with your hand, and pull the trigger (no BB's, obviously). If the gun fires, then you have successfully reset the gearbox. If not, try resetting a few more times.

After resetting the gearbox, put everything back in reverse of your disassembly.

More Optimal Procedure

You can save yourself some time from having to remove the handgrip if you make an anti-reversal latch resetting tool that is longer than the handgrip. Then you can just reach in from outside the handgrip to reset the latch. The only difficulty is find a hard metal wire that is long enough.